Dentists chair



(No Model.)

W. A. JOHNSTON & A. W. BROWNE.

DENTISTS GHAIR.

No. 340,787. Patented Apr. 27, 1886.

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UNITED STATES PATENT OFFICE.

VILLIAM A. JOHNSTON, OF CLIFTON, AND ARTHUR IV. BROIVNE, VOF WEST-FIELD, N EIV YORK, ASSIGNORS TO THE S. S. VHITE'DENTAL MANUFAC- TURINGCOllIPANY, OF PHILADELPHIA, PENNSYLVANIA.

oENTlsTs CHAIR.

@TPLECEFCATION forming part of Letters Patent No. 340,787, dated April27, 1886.

Application filed June 10, 1885. Serial No. 169,247. (No model.)

To all whom it may concern:

Be it known that we, VILLIAM A. JOHN- sToN, of the village of Clifton,in the county ofV Richmond and State of New York, and

5 ARTHUR XV. BRowNE, of the village of XVestfield, in said county andState, have jointly invented certain new and useful Improvements inDentists Chairs, of which the following is a specification.

Our invention relates to adjustable chairs more especially designed forthe use of dentisfs.

The object ofour invention is to give an in` creased range of verticaladjustment to the I5 chair-seat, so that the patient seated in the chairmay be elevated to the highest point desired, or lowered to the lowestpoint desired,

(or held at any intermediate point,) in the practical operations of thedentist, whether 2o the operator be a tall or a short person.

To this end our invention consists in extending the elevating andsupporting apparatus of the chair below the chair-base or pedestal,which rests upon the floor or platform of 25 the operating-room.

Heretofore in operating-chairs, the chain base or pedestal has beensupported upon the iioor by suitable legs and feet, while the ele-vating apparatus has been mounted in or up- 3o on said base orpedestal, b ut not extending below it. XVe do not here refer to thatclass of operatingeliairs wherein there is a supporting bar or post atthe back of the chair body or seat, on which the chair body or seat 3 5is iitted to travel and be supported. By this arrangement limitedvertical adjustment of the chair body or seat has been the result,because if a wide range of upward movement was desired, the base orpedestal was neces- 4o sarily long in order to inclose the elevatingparts of the apparatus. Consequently it was impossible to bring thechair-seat down close to the licor, because the base or pedestal wouldnot permit such an operation. Oper- 45 ating stools and seats weretherefore necessarily employed by the operators, so to place themselvesin the proper altitude to conduct the dental operations. On thecontrary,were the base a low one, the patient seated in the chair mightbe brought down close to the door, 5o but a high range of adjustment oraltitude could not be effected.

By our improvement we employ a low base, which enables the chair body orseat to be brought as low down as is necessary to meet 55 any practicalrequirements, and by extending the elevating part of the apparatus belowsaid base-21s, forinstance, through the oorwe employ lengthenedelevating apparatus, by which the chair body or seat may be raised to 6oany desired height, and this because the elevating part of the apparatusis not conined in length to correspond with the base or pedestal.

Our invention further consists in certain new 6 5 organizations andcombinations of devices, which are particularly recited at the close ofthe specication.

In the accompanying drawings, Figure l is a perspective view of our`improved chair or- 7o ganized in the best way now known to us. Fig.

2 is a sectional view of the lower portion of the base or pedestal andelevating devices. Fig.

3 is a similar View to Fig. 2, with the exception that the base, exceptits plate B, isin ele 75 vation.

The base or pedestal of the chair is preferably made up of a tubularcasting, A, having a lower, enlarged, or daring end secured or bolted toa plate, B, which is in turn fastened 8o to the 'floor by suitablefastenings. This plate B is preferably a circular plate, and is providedpreferably with flaring or tapered edges I), so that the carpet may befitted upon and over lsaid plate B without affording sharp edges, by 8 5'sented by D, and it will thus be seen that the well C is passed throughthe flooring and between two of the joists D D', supporting saidflooring, whereby a part of the chair is while it may be elevated to anydesired height extended below the base and through an opening in thefloor.

The elevating apparatus consists in this example of a plunger, E, andits supporting and operating connections, upon the upper end of whichplunger the chair-body or seat-frame is mounted. Said plunger is fittedto work up and down in a cylinder, F, which is fitted at its lower endwith a valve-frame, G. Said valve-frame Gis fitted with one or morevalves,

. which constitute the means of communication between the cylinder F, inwhich the plunger T moves, and the well C. The upper end of the cylinderF is enlarged or provided with a cap, F2,which rests upon the upper endof the tubular base A, and is fitted to turn or swivel thereon,wherebythe chair-body may be turned around horizontally to afford horizontaladl]'ust1nent,while it may belocked in the desired position by means ofa clamp-screw, f, passing through the base A, and bearing against theside of thecylinder F. The cap F2 of the cylinder F is slotted andfitted with lugs, between which an elevating-lever, H, is pivoted, theinner end of said lever carrying connections which act upon the plungerE to elevate it in the cylinder F when the pedal end of theelevating-lever is depressed. The operating connection between theelevating-lever H and the plunger E may be a lifting-pawl 011 the end ofsaid lever, engaging teeth on the plunger. By depressing the elevatirig-lever, which is a pedal-lever preferably, thc plunger is elevated inlthe cylinder, while the fluid which is contained in the well C followsthe plunger in its ascent and supports it in its elevated position bythe closing of the valves. By opening one of the valves the fiuid isdisplaced and the plunger permitted to descend to lower the chair -body.This elevating, lowering, and supporting apparatus is substantially thesame as that shown in Vilkersons patent of November 20, 1877, and E. T.Starrs patentsof November 25, 1879, and April l2, 1881, and need not bedescribed in detail, as our invention is not limited to the particularform of elevating and supporting apparatus shown.

By the organization shown, a long plunger or support for the chairseatmay be employed, as it is free to move not only th rough the base, butbelow the base and through the fioor or a platform, on which the basemay rest, for the required distance, whereby the chair may be broughtdown as low as desired to the door,

required in practical operation.

We do not claim herein anything shown in N ewbroughs patent of November16, 187 5, which shows a rack-bar or post mounted upon and extendingabove the floor of the operating room, and fitted with a travelingchair-body, adjustable up and down thereon and in front thereof; nor dowe claim herein anything shown in the German Patent No. 23,446, 0f

1883, which shows a series of theater-chairs tted to move up and downthrough holes in the floor of the theater, and elevated and loweredrelatively to said oor, by a plunger or series of plungers beneath thefloor and working in a cylinder or cylinders located in a pit or pitsbeneath said floor.

XVe claim as our invention- 1. The combination, in an operatingchair, ofa base or pedestal resting upon the fioor or platform of theoperating-room, a chair body or seat elevating and supporting mechanismmounted in said base and extending below said base or pedestal throughthe iioor or platform on which it rests, and a turning or swivelingconnection between said elevating and supporting mechanism and said baseor pedestal, substantially as described, whereby increased range ofvertical adjustment is imparted to the seat or body of the chair withoutinterfering with its turning or horizontal movements relatively to thebase thereof.

2. The combination of a hollow base or pedestal, a base-plate or supportbolted or secured thereto, and a fluid cell or reservoir fastened tosaid base-plate and extending below it, substantially as described.

3. In combination with the floor or platform of an operating-room, anoperating-chair consisting of a base or pedestal resting on said iiooror platform, elevating and supporting mechanism mounted upon said baseand eX- tending below it through the floor or platform, operatingmechanism by which said elevating mechanism is controlled mounted abovesaid floor or platform, and the chair-seat or chairbody mounted uponsaid elevating and supporting mechanism,substantially as described.

In testimony whereof we have hereunto subscribed our names.

`WILLIAM A. JOHNSTON. ARTHUR XV. BROVNE. lVitnesses: I

HUBBARD R. YETMAN, LLOYD B. VUGHT.

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